1. Field of the Invention
The invention relates to an improved control assembly for a permutation type lock. More specifically, the invention relates to such a novel control assembly which permits a low profile lock. The invention also relates to such a control assembly having a removable code gear arrangement.
2. Description of Prior Art
Control assemblies for permutation type locks are known in the art as illustrated in, for example, U.S. Pat. No. 3,040,556, Rosenhagen, June 26, 1962. In the Rosenhagen patent, the control assembly includes a code gear arrangement, an idler gear arrangement and a timing gear arrangement. Push buttons are provided to punch in a code, and a plunger extends from each push button to move a respective code gear of the code gear arrangement when the push button is pushed. As the plunger moves in the same direction as the movement of the push button, a control assembly for a permutation lock made in accordance with the teachings of the Rosenhagen patent must have a relatively high profile.
Furthermore, with a control assembly as taught in Rosenhagen, if the combination is "lost" (i.e., it is forgotten), then the entire assembly must be taken apart to reset the assembly.
U.S. Pat. No. 3,115,765, Fengler, Dec. 31, 1963, makes improvements to the control assembly of Rosenhagen. However, it does not alter the performance insofar as the above-mentioned disadvantages.
U.S. Pat. No. 3,411,330, Atkinson, Nov. 19, 1968, teaches a system wherein the combination is dialled instead of using push buttons.
U.S. Pat. No. 4,027,508, McGourty, June 7, 1977 provides a push-button combination lock wherein a new combination can be set without dismantling the lock.
U.S. Pat. No. 4,111,017, Barnette, Sept. 5, 1978, teaches a manually operated coded switch. After attempting a code, the switch's code wheels must be returned to their zero position before another try can be made.
U.S. Pat. No. 4,445,348, Saitoh, May 1, 1984, teaches a combination lock capable of being set in any desired combination of numbers without the use of tools.